Novel electrolytic amalgam denuder apparatus

Abstract

An improved process for the production of halogens and alkali metal hydroxide by electrolysis of aqueous solution of alkali metal halides in a flowing mercury electrolysis cell wherein the salt solutions do not have to purified and to novel amalgam denuders and a mercury electrolytic cell plant without a salt purification step.

We claim: 
     
       1. An amalgam denuder comprising a container filled with a catalytic material, means for introducing amalgam at the top of the container, means for introducing water at the bottom of the container, means for removing hydrogen at the top of the container, means for removing alkali metal hydroxide solution at the top of the container, a divider plate separating the container from a chamber provided at the bottom of the container for collecting mercury and provided with a negatively charged counter-electrode above the mercury and water and means for removing mercury from the chamber. 
     
     
       2. An electrolytic amalgam denuder comprising a housing provided with a vertical series of horizontal porous plates made of an electrically conductive material, the said plates being electrically insulated with respect to adjacent plates, means for impressing a voltage of about 0.2 to 0.4 volts between adjacent plates, means for introducing water in the lower portion of the housing, means for introducing amalgam at the upper portion of the housing, means for removing hydrogen and means for removing alkali metal hydroxide solution at the top of the housing and means for removing mercury from the bottom of the housing, the upper most and lower most plates not having an electric current impressed therein. 
     
     
       3. The denuder of claim 2 wherein the plates are provided coaxial holes with a weir to provide a chimney-like effect for hydrogen passage. 
     
     
       4. The denuder of claim 3 wherein the plates are made of graphite.